The Great ShakeOut: Earthquakes Affect Reactors, Too

February 8, 2012
David Wright
Former contributor

Yesterday (Feb. 7) was the Great Central-U.S. ShakeOut aimed at helping people in that part of the country learn some of the ways to protect themselves from earthquakes. While people on the west coast know about the risk of earthquakes, several decades ago the U.S. government determined that the hazard posed by seismic activity in the central and eastern parts of the country was greater than previously believed.

So The Great ShakeOut is helping people learn the basics of protecting themselves if things start to shake, including:

  • DROP to the ground (before the earthquake drops you!),
  • Take COVER by getting under a sturdy desk or table, and
  • HOLD ON to it until the shaking stops.

But these steps will only protect you from some kinds of risks. They won’t help if a nearby nuclear power reactor hasn’t been designed to withstand the tremors.

After recognizing the higher seismic risks in the central and eastern parts of the U.S., the Nuclear Regulatory Commission (NRC) enacted regulations in 1996 that required new reactors built in these areas to be designed with protection against the greater hazard. But the NRC did nothing about seismic protection at existing reactors operating in these areas for the next decade.

In summer 2005, the NRC began examining the potential risk from reactors operating with less protection than necessary against the known seismic hazard. The NRC’s studies identified the 27 most vulnerable reactors based on current information. The NRC has not required the known protection shortcomings to be resolved, even at the high risk reactors. As a result, many of these reactors remain at higher risk of damage from earthquakes than they should be.

The NRC knows how to increase the safety of nuclear reactors against earthquakes. For example, its 1996 regulations require new reactors that are built in areas prone to earthquakes to use designs that have been developed to provide extra seismic protection. Moreover, several existing plants have built in structural modifications, such as better pipe supports, that increase the protection of the reactor against seismic activity. But the NRC has not required such modifications.

So maybe the next step is to organize a Great Shake-Up at the NRC to get it to move forward on this issue.

To see these 27 reactors, go to the UCS Nuclear Power Information Tracker, check the box for “Earthquake Risk” and click “Refresh Map.”